Seeing a city wall signifies fighters striving in the path of Allah, the head of state, the civil governor of the city, and its guardian.
Seeing unknown towers and walls signifies Islam, knowledge, the Qur'an, wealth, security, piety, and prayer. At times, walls signify a scholar and worshipper, the religious rulings that distinguish truth from falsehood, joy, happiness, and relief. Standing on a wall signifies protection from an enemy and safety from what one fears.
Seeing the towers of a city demolished signifies the death of that city's governor or guardian.
Seeing a breach opened in a city's towers or walls through which a lion, flood, or thieves enter signifies weakness of Islam in that city, the strangeness of knowledge, and the increase of ignorance.